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Finding the Fourth Proportional to 309.15, 461.28 and 278.49

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Solution

The fourth proportional to 309.15, 461.28 and 278.49 is: 415.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.15 : 461.28 = 278.49 : x
  2. Step 2: Convert to fraction form
    309.15/461.28 = 278.49/x
  3. Step 3: Cross multiply
    309.15x = 461.28 × 278.49
  4. Step 4: Simplify right side
    309.15x = 128,461.87
  5. Step 5: Solve for x
    x = 128,461.87/309.15
  6. Step 6: Final answer
    x = 415.53

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.